A Ca(2+)-activated NADPH oxidase in testis, spleen, and lymph nodes.
J Biol Chem
; 276(40): 37594-601, 2001 Oct 05.
Article
en En
| MEDLINE
| ID: mdl-11483596
ABSTRACT
Superoxide and its derivatives are increasingly implicated in the regulation of physiological functions from oxygen sensing and blood pressure regulation to lymphocyte activation and sperm-oocyte fusion. Here we describe a novel superoxide-generating NADPH oxidase referred to as NADPH oxidase 5 (NOX5). NOX5 is distantly related to the gp91(phox) subunit of the phagocyte NADPH oxidase with conserved regions crucial for the electron transport (NADPH, FAD and heme binding sites). However, NOX5 has a unique N-terminal extension that contains three EF hand motifs. The mRNA of NOX5 is expressed in pachytene spermatocytes of testis and in B- and T-lymphocyte-rich areas of spleen and lymph nodes. When heterologously expressed, NOX5 was quiescent in unstimulated cells. However, in response to elevations of the cytosolic Ca(2+) concentration it generated large amounts of superoxide. Upon Ca(2+) activation, NOX5 also displayed a second function it became a proton channel, presumably to compensate charge and pH alterations due to electron export. In summary, we have identified a novel NADPH oxidase that generates superoxide and functions as a H(+) channel in a Ca(2+)-dependent manner. NOX5 is likely to be involved in Ca(2+)-activated, redox-dependent processes of spermatozoa and lymphocytes such as sperm-oocyte fusion, cell proliferation, and cytokine secretion.
Buscar en Google
Bases de datos:
MEDLINE
Asunto principal:
Bazo
/
Testículo
/
Calcio
/
NADPH Oxidasas
/
Ganglios Linfáticos
/
Proteínas de la Membrana
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
/
Male
Idioma:
En
Revista:
J Biol Chem
Año:
2001
Tipo del documento:
Article
País de afiliación:
Suiza